Free-jet turbine



G. TREFZ ET AL FREE JET TURBINE Filed Dec. 21. 1925 2. Sheets-Sheet l l :L T f 5% mme/v..

Nw. 22, 927., 1,650,475 G. TRI-:FZ ET AL FREE JET TURBINE Filed nec.21. 1925 2 Sheets-sheet? Patented Nov. 22,1927.

i 1,656,415 UNITED STATES PATENT-oFF1cE.

vGUSTAV TREFZ AND FRIEDRICH TREFZ, F GROSSASPACH, GERMANY.

FREEJET frURBIim.

Application led December 21, 1925, Serial No. 76,740, and in Germany August 22, 1925.

This invention relates to free jet` turbines, and has for its main object to assure that the impact fluid enters over the whole periphery of the rotor with perfect equality as regards volume and direction` so that'even if a single blade rotor is einployed a perfectly uniform running and a uniform load on the turbine is obtainedja further object is to' prevent the formation of a vacuum -between lo the blades of the rotor in order to assure that the impact iiuid runs away from the rotor after it has imparted energy thereto; a further obj ect is to prevent choking of the rotor wheel by the impact uid so as tol prevent i5 the turbine being converted into an excess pressure turbine, which, as is well known, obtains an inferio'i` action owing to the unfavourable outletwangle; and a still further object is to assure a continuousinflux of air between the rotor Wheel blades so that the jets of impact fluid lowfreely away, thereby assuring that the turbine acts as a true free jet turbine. ,f

A. construction according to the present invention comprises the combination with the rotor, of a casing adapted tofconstrain the impactfluid to move to the rotor as a compact spiral body, lspiral deflectors being disposed inthe casing so as to divide up the Huid body and divert -predetermined portions thereof in such a way thatl equalquantities of the fluid flow in similar spiral streams to the rotor and enter the rotor simultaneously around its whole periphery, at the same angle,.whereby every one of the rotor blades always receives the same impact whatever the angular position of the rotor.

The accompanying drawings illustrate a preferred construction embodying` the present invention: y

Fig. 1 is a diagrammatic axial section through the turbine;

Fig. 2 shows diagrammatically/the course of the guided jets of water; j

Fig. 3 shows the same with the corresponding guide blades and a few of the rotor blades; and

' Fig. 4 is a horizontal Jcross-section through the turbine on the line 4--4 of Fig. 1.

The rotor wheel a of the turbine is 'proided in known manner with blades b, the whee'l being mounted in a casing 0 adapted to constrain the Huid to flow in a compact 55 spiral body to the turbine (see Fig. 2), spiral deiiectors d (see Figs. l and 3) being proariesof the consecutive streams, for instance,

the boundaries of the innermost stream are m1 and m2 and the boundaries of the outermost stream are m1 and m5. It will be noticed, therefore, that the streams are a'lways in contact with one another--hence the compact body referred to--and that the streams never deviate from' the spiral at any point, whereby the rotor blades b are oon-` tinuously impinged upon in the desired direction. The outside stream of water flows adjacent the casing wall and thus the last deiiector is shown as a portion of the casing wall d in Fig. 4. j V

Referring particularly to Fig. 3, which rclearly shows the division of the body of the water, each stream forming a. jet of spiral form, the jets being identified by the reference-s nl to n4, which jets of necessity run parallel with each other and touch each other,

each jet inipinging on a quadrant of the rotor so that the four jets impinge simultaneouslyy on the whole of the periphery of the rotor, so that there must be perfect uniformity at all points as regards volume and pressure, as the jets always enter the rotor wheel at the saine distance from the axis thereof; `thereby the impact never varies at any point, and is directed always at the same angle. It will be clear that the number of impact or admission jets maybe varied, the number varying according to the size of the turbine wheel, and further, that the number of rotor blades is without limitation. yIt has, however, been found in practicethat it is desirable that the width of the whole body of impact fluid measured in a planenor mal to the axis, be about half the diameter of the suction openin e and this proportion of body ofimpact- Huid to the opening is illustrated in the drawings.

Now in order to prevent such a turbine v side of the rotor; to this end a circular cover f is attached to the rotor wheel and is provided With a sleeve g extending over the turbine shaft z' but spaced therefrom so as to provide an air passage It over the shaft; the cover f, it will be noticed, touches the -periphery of the rotor wheel, but otherwise is spaced therefrom, thereby providing the chamber Z between the wheel audits cover f; this chamber is, through the space h, connected to atmosphere, and therefore also atmospheric air can pass to and through the openings c to the other side of the blade when the pressure on that side falls below the pressure of atmosphere; this arrangement assures a continuity of flow of the impact water after energy has been imparted to the rotor blades. Instead of a single chamber a number of'chambers may be provided. Fig. 4 is a section through the deflector and partly through the chamber l in which partitions Z are arranged therein to form a number of chambers.

By the arrangement described formation of a vacuum between the rotor blades is prevented from forming due to the suction action of the water jets in the rotor wheel cells, which vacuum will produce, together with the centrifugal force set up, an accumulation between the blades of the impact Water, and therefore a choking of the rotor wheel, and if the rotor wheel is full the turbine would act as an excess pressure turbine and not as a free jet turbine, which undesirable conversion of motor working, therefore, is entirel prevented.

e claim 1.'In a free-jet turbine, the combination with the rotor, of a casing; and a plurality of deflectors each spirally arranged in the casing in the path of the motive fluid so that the motive fluid shall be spirally directed into the rotor, whereby the single streams of motive fluid will form a constrained stream of similar spiral form upon the entire pecasing arranged to form a chamber with the rotor, the cover being provided with a sleeve which surrounds the turbine shaft in spaced relation andthrough which the Aoutside air communicates with the chamber; and a plurality of deflectors spirally arranged in tht` casing in the path of the motive fluid so that the motive fluid shall be spirally directed into the rotor, whereby the .single stream of motive fluid will form a constrainefl stream or' similar spiral form upon the el. rire periphery of the rotor.

55. In a free-jet turbine, the combinatie.. with the rotor, ol a casing; a cover in said casing arranged to form a chamber with the rotor, the cover being provided with a sleeve which surrounds the turbine shaft in spaced relation and through which the outside air communicates with the chamber, and the rotor having openings adjacent the periphery communicating with the chamber s0 that the air can equalize the pressure on both `Aides of the blades; and a plurality of deflectors spirally arranged in the easing in the path of the motive fluid so that the motive fluid shall he spirally directed into the rotor, whereby the single stream of motive fluid will form a constrained stream of similar spiral form upon the entire periphery of the rotor.

4. In a free-jet turbine, the combination with the rotor, of a casing; a cover in said casing arranged to form a plurality of chambers, the cover being provided with a L'leeve which surrounds the turbine shaft in spaced relation and through which the outside air communicates with the chamber; and a plurality of detlectors spirally arranged in the casing in the path of the motive fluid so that the motive fluid shall be spirally directed into the rotor, whereby the single stream of motive fluid will form a constrained stream of similar spiral form upon the entire periphery of the rotor.

In testimony whereof we afiix our signa-` tures.

GUSTAV TREFZ. FRIEDRICH TREFZ. 

